Method of increasing a vapour compressing refrigerating machine cooling effect



Aug. 16, 1966 L. M. ROSENFELD ETAL 3,266,258

METHOD OF INCREASING A VAPOUR COMPRESSING REFRIGERATING MACHINE COOLING EFFECT Filed Aug. 15, 1964 Ill 1111mm! M MHHHHHHHI United States Patent METHOD OF INCREASHNG A VAPUUR COMPRESS- ING REFRIGERATING MACHINE COOLING EFFECT Lev Markovich Rosenfeld, Leningrad, Vjacheslav Valerjanovich Arlrhangelslry, Lyuhertsy, and Ilia Lvovich Gerlovin, Leningrad, all of U.S.S.R., assignors to Leningradsky Telrhnologicheslry Institute Cholodilnoi Promyshlennosti Filed Aug. 13, 1964, Ser. No. 389,402

8 (ll-aims. (Cl. 62-3) The present invention relates to refrigerating techniques and more particularly to increasing and regulating the cooling effect of vapor type refrigerators.

As is known, the present methods of regulating of the cooling effect of vapor type refrigerators containing an evaporator, a compressor, a condenser and a thermostatic valve, are based on a change in the amount of a refrigerant circulating in the system. In such as case irreversible losses in the vapor type refrigerator increase, thus resulting in a reduction in its energy efficiency.

Installation of water cooler ahead of the thermostatic valve to cool the refrigerant for increasing the refrigerators cooling effect is not too successful, since there is only a small reduction in the refrigerant temperature before reaching the thermostatic valve.

An object of the present invention is to increasing the cooling effect of vapor type refrigerators by reducing the energy losses in the refrigerant circuit.

Another object of the invention is to provide for smooth regulation of the cooling effect of vapor type refrigerators without changing the amount of the refrigerant circulating in the system.

A further object of the invention is also to provide a device to be used for additional cooling down of the refrigerant upstream of before the thermostatic valve to such as temperature so as to eliminate large energy losses during a choking process in the thermostatic valve.

According to the invention this problem is solved by employing a method of increasing and regulating the cooling effects of a vapor type refrigerator by additional 1 cooling down the refrigerant to its vaporizing temperature by a thermoelectric cooler interposed between the condenser and the thermostatic valve in the cooling circnit.

When this method is used, the energy efficiency of the system comprising a vapor type refrigerator and a thermoelectric cooler depends upon the relationship of the specific cooling effect of the vapor type refrigerator and of the thermoelectric cooler.

The statement described above can be illustrated with the following formula:

K =Q +AQ /N +AN cal./ kw. hr.

where K (cal./ kw. hr.)--overall specific effective cooling effect;

Q (cal./hr)-vapor type refrigerator cooling effect;

AQ (cal./hr.)additional cooling effect, obtained due to cooling of refrigerant in the thermoelectric cooler;

N (kw.)vapor type refrigerator effective power;

AN (kw.)efi'ective power consumed in the thermoelectric cooler.

tion of the cooling effect by changing the amount of electric power supplied into the thermoelectric cooler.

Besides, regulation can be ensured by means of varying the number of thermal elements in operation.

In accordance with the invention, the method is preferably carried out by using a thermoelectric cooler, comprising a tube, ribbed on the inside and anodized on the outside, on which are fixed cooler sections (prisms with thermal elements). The sections are connected on the hot junction sides by centrally apertured copper plates. Brought through the central holes of the copper plates is a displacer. Between the outer surface of the displacer and the inner surface of the plates, a ring-like channel is defined for permitting circulation of a medium for cooling the hot junctions via the copper plates.

Other objects and advantages of the invention will be apparent from the following description below when read with the accompanying drawings:

FIGURE 1 illustrates the operation cycle on an S-T diagram of a vapor type refrigerator with a thermoelectric cooler in accordance with the invention;

FIGURE 2 shows schematically the refrigerant circuit of the apparatus for carrying out the invention;

FIGURE 3 is a sectional view of the thermoelectric cooler; and

FIGURE 4 is a sectional view taken along the line I-I of FIG. 3.

With the system operating, the refrigerant from evaporator 1 having a temperature T is fed into compressor 2 which corresponds to point a in FIG. 1, is compressed there (point b) and delivered into condenser 3, where it is condensed at temperature T (point c"). If no thermoelectric cooler where in the system, the refrigerant would be fed directly to thermostatic valve 4 (point d) and then into the evaporator 1, where it vaporizes and provides the cooling effect Q dependent upon the area in rectangle a d f k of FIG. 1.

If however, a thermoelectric cooler is used, the refrigerant from condenser 3 is supplied to thermoelectric cooler 5, where it is cooled down to the vaporizing temperature (point e in FIG. 1); then the refrigerant is delivered into evaporator 1, where it provides for the cooling effect, which is greater by value AQ. and depends upon the area of the rectangle a e n k.

The thermoelectric cooler 5, shown in FIG. 3 comprises aluminium tube 6. The internal surface of tube 6 is provided with fins 7 to increase the thermal exchange surface 7 and turbulence of the refrigerant flow.

Secured on the external surface of tube 6 are sections 8 of the cooler, which are copper prisms 9 (FIG. 4) each having a hole 10 along the diameter of tube 6 and a slot 11, said prisms being effective to brace sections 8 and to provide for their good thermal contact with tube 6.

To prevent corroding of sections 8, the external surface of tube 6 is anodized.

Semi-conducting thermal elements 12 are assembled on the opposite faces of sections 8. Thus, each section 8 is a cold junction of a thermo-couple.

The hot junctions 13 of the thermal elements are connected with copper plates 14 so, that they provide for consequent passing of current through the thermal elements of all sections. Displacer 16, a heat flow diffuser, brought through holes 15 of plates 14, serves to build up flow turbulence and to improve the thermal efiiciency of the hot junctions.

In the above-described structure, the refrigerant enters aluminium tube 6 and passes therethrough. The thermal elements 12 increase in size in the direction of refrigerant flow thereby reducing the temperature of the refrigerant as it passes through the tube with a minimum temperature differential existing between the refrigerant and the cold junctions along the entire refrigerator.

Patented August 16, 1966 Thus, at the cooler outlet the refrigerant temperature corresponds to the rated value, defining the cooling effect of the cooler.

To cool down hot junctions 13, coolant, for instance water, is introduced through pipe connection 17 from the side of the sections with the thermal elements of greater size, and is discharged at the opposite side. Temperature reduction is adjusted by changing the amount of electric power supplied to the cooler or by varying the number of the thermal elements in operation.

Although the present invention as described herein before refers to a preferred embodiment, it is evident that some changes and modifications may be made without departing from the spirit and scope of the invention, which can be easily understood by those skilled in the art.

Such changes and modifications are considered to fall within the scope and spirit of the invention as defined by the appended claims.

What is claimed is:

1. In a vapor type refrigerator which includes a compressor, an evaporator, a condenser, a thermostatic valve, a first conduit connecting said compressor to said evaporator, a second conduit connecting said compressor to said condenser, a third conduit connecting said condenser to said thermostatic valve, a fourth conduit for connecting said thermostatic valve to said evaporator and refrigerant circulating in said conduits, a thermoelectric cooler about said third conduit for lowering the temperature of refrigerant in said third conduit comprising a plurality of cooler elements, each of said cooler elements including a copper prism disposed around said third conduit and provided with side faces, semi-conductor thermoelectric junction elements disposed against said side faces and extending beyond the ends of said prisms, the interface between said semi-conductor thermoelectric junction elements and the side faces of said prisms being adjacent the regions of the cold junctions of thermoelectric junction elements, further apertured copper elements abutting the extending portions of said thermoelectric junction elements, the interface between said extending portions and said further apertured copper elements being adjacent the regions of the hot junctions of said thermoelectric junction elements, and means for feeding coolant through the apertures of said further apertured copper elements for reducing the temperature of the hot junctions.

2. The thermoelectric cooler of claim 1, wherein the size of the semi-conductor thermoelectric junction elements increases in the direction of flow of refrigerant in said third conduit so that the cold junctions are at progressively lower temperatures.

3. The thermoelectric cooler of claim 1, wherein the coolant is fed sequentially through the apertures of said further apertured copper elements in a direction opposite to the flow of refrigerant through said third conduit.

4. The thermoelectric cooler of claim 1, wherein corrugated coaxial bands are soldered to the inside of said third conduit.

5. A thermoelectric cooler comprising a conduit adapted to pass a fluid to be cooled, a plurality of semiconductor thermoelectric elements including hot junctions and cold junctions disposed progressively along said conduit, means for thermally connecting said cold junctions to said conduit, said thermoelectric elements progressively increasing in size in the direction of fluid flow through said conduit so that the temperature of said cold junctions progressively decrease in said direction, and heat transfer means thermally connected to the hot junctions for extracting heat therefrom.

6. The thermoelectric cooler of claim 5, wherein said heat transfer means includes conduit means thermally connected to each of said thermoelectric elements for channeling coolant in a direction opposite to the passage of fluid through said conduit.

7. The thermoelectric cooler of claim 5, wherein corrugated coaxial bands are soldered to the inner surface of said conduit.

3 The thermoelectric cooler of claim 5, wherein said means for thermally connecting said cold junctions to said conduit comprises apertured copper prisms disposed about said conduit and including faces in contact with the col-d junctions of said thermoelectric elements.

References Cited by the Examiner UNITED STATES PATENTS 413,136 10/1889 Dewey 623 1,831,861 11/1931 Henney 62-222 2,091,159 8/1937 Persons 62-305 2,294,036 8/ 1942 Kettering 62323 2,311,294 2/ 1943 Hanson 62208 2,950,740 8/1960 Bock 179 3,054,840 9/1962 Alsing 623 WILLIAM J. WYE, Primary Examiner. 

1. IN A VAPOR TYPE REFRIGERATOR WHICH INCLUDES A COMPRESSOR, AN EVAPORATOR, A CONDENSER, A THERMOSTATIC VALVEA FIRST CONDUIT CONNECTING SAID COMPRESSOR TO SAID EVAPORATOR, A SECOND CONDUIT CONNECTING SAID COMPRESSOR TO SAID CONDENSER, A THIRD CONDUIT CONNECTING SAID CONDENSER TO SAID THERMOSTATIC VALVE, A FOURTH CONDUIT FOR CONNECTING SAID THERMOSTATIC VALVE TO SAID EVAPORATOR AND REFRIGERANT CIRCULATING IN SAID CONDUITS, A THERMOELECTRIC COOLER ABOUT SAID THIRD CONDUIT FOR LOWERING THE TEMPERATURE OF REFRIGERANT IN SAID THIRD CONDUIT COMPRISING A PLURALITY OF COOLER ELEMENTS, EACH OF SAID COOLER ELEMENTS INCLUDING A COPPER PRISM DISPOSED AROUND SAID THIRD CONDUIT AND PROVIDED WITH SIDE FACES, SEMI-CONDUCTOR THERMOELECTRIC JUNCTION ELEMENTS DISPOSED AGAINST SAID SIDE FACES AND EX- 